Grinding machine



March 6, 1945. 1 B. PORTMAN ET AL GRINDING MACHINE Filed sept. 21, 1942 2 Sheets-Sheet 1 'March 6, 1945. L E, PORTMAN ET'AL 2,370,813

GRINDING MACHINE Filed Sept. 2l, 1942 2 Sheets-Sheet 2 AT ORNEY Patented Mar. 6, 1945 vyUNITED# SITA-TES Frank J.Acton,`Mount-Vernon, N.-

Applica-ffm September 21, 1942-; s'erialfmto; 932W ef side-i of the .g Column. 25 as will 'bezug-..2 v

duction in speed and movementl between the hand wheel 46 and the screw shaft 34, so that large movements of the hand wheel effect only minute movements of the support 25 in progressive increments to afford extremely accurate adjustment of the grinding element to the work. For example, the hand wheel may be graduated in .0005 with one complete revolution of the wheel 46 equalling .050" of movement of the support 25 in the column 26. A pointer 41 mounted on the column 26 cooperates with the dial markings on the hand wheel 46.

The counterbalancing arrangement comprises a pair of coiled springs 5l respectively attached at one end to an eye bolt 52 mounted in a shelf 53 which is integral with the support 25 and extends rearwardly therefrom near its top. The springs are located on opposite sides o f block 33 and at their opposite ends the springs are respectively attached to one end of a pair of levers 54. These levers fulcrum upon jack shaft 55 mounted in wings 56,which extend rearwardly from the support 25. It will be noted that the fulcrum 55 is very close to ,the axes'of the springs 5l and that the end of the lever 54 to which each spring is connected has a very short radius. The opposite end of each lever 54 is much longer and extends upwardiyat an acute angle to the wings 56. The outer end of each lever has pivoted thereto the lower link of a chain 51 and the opposite ends of the chains also are pivotally connected to blocks 58 carried on the ends of mounting screws 59 located near the top of the column 26. This arrangement allows for the shifting of the pivots for the outer ends of the levers 54 as the support is raised and lowered, and insofar as the function in this mechanismis concerned, these chains 51 could be replaced by rods having the same pivotal connections.

It will be evident that the weight of the support 25 and the mechanism carried thereby is sustained by the column 26 through the chains 51 and levers 54 with their attachment to the support and that this weight is counterbalanced bythe tension of the spring 5I attached to the levers54. y

The-raising and lowering of the grinder head is accomplished by rotation of the hand wheel 46 to rotate the screw 34 which causes the block 33 ofthe support 25 to travel along the screw thus eievatingvor lowering the support. As the support is elevated the springs 5I and their levers 54 are carried therewith, causing the levers to move about the pivotal connection thereof with the chains 51. It is true that by reason of the straight line vertical movement of the levers there is a pivoting of the levers about the fulcrum 55, but this movement is only very slightly in excess ofthe amount of the vertical adjustment. Consequently, there is very little movement of the springs 5I and very little variation in the tension thereof as the grinder head is vertically adjusted. With such counterbalancing and drive the vertical adjustment is easily and accurately made. At the same time all the counterbalancing and other mechanism is housed in the column 26.

There is one further adjustment for bringing the grinding element in accurate alignment with the work. The column 26 is itself pivotally mounted on a slidable table 6l by means of a shaft 62 that is journaled in a pair of lugs 63 on the table and in bosses 64 on the side walls of column 26. lt will be noted that the axis of the shaft lt2- is perpendicular to the axis of the bolt 21 around which the grinder head is adjustable from side to side. Adjustment of the column 26, on which the grinder head with its motor is supported, will tilt the head in a plane from front to rear of the machine and permit the grinding of concave surfaces.

The adjustment about the axis of the shaft 62 is done by means of an adjusting screw 66 which is adjustable in a lug 61 at the rear of column 26, the screw abutting against a boss 68 on the table 6l. A lock nut 69 cooperates with the adjusting screw to hold the same in its adjusted position. To prevent vibration of the column, etc., a bolt 10 is passed through an enlarged central hole 1| in the adjusting screw and engages in a threaded hole 12 in the table 6l. When the bolt 69 is screwed home the head thereof engages the head of the adjusting screw 66.

The slidable table 6| has a flange 15 on opposite sides thereof which anges extend into channel shaped trackways formed by angle iron 16 mounted on base Il, and an overlying guide plate 11 secured thereto. The table is supported upon four or more rollers or wheels 18 .for sliding movement along the trackway, for which purpose a rack 19 is afiixed to the bottom of the table. Pinion 8l (Fig. 1) meshes with this rack and is fast upon shaft 82, suitably mounted in base ll and having on the outer end thereof pilot wheel 83. Rotation of the pilot wheel moves the table backward and forward, carrying the grinder head from and to the work held by the chuck l2.

Alignment of the table is accomplished in the following manner: Each supporting wheel 18 is mounted in a truck 84 (Figs. 6 and 1) having front 'and rear projections 85, 86, which with vertical ears B1 dene a space in which wheel 18 is rotatably mounted. The under side of the table flange 15 is cut away, as indicated at 88, to receive the ears 81 of each truck and the upper half ofthe wheel 18 carried thereby. There is a ball and socket connection between each truck and the table formed by a depression in the top of the rear projection 86 of the truck in which a ball 89 rests, the under side of the flange 15 have ing a somewhat similar depression into which the ball 89 also fits. The arrangement is such that there is a space between the top of the projection 86 and the flange 16 so that the truck maybe tilted about the axle of the wheel 18. For' this purpose the front, projection 85 of the truck has a depression therein which receives the pointed end of an adjusting screw 9i which is adjustable in the adjacent flange 15 of the table. This is the equivalent of a second ball and socket connection between the table and the supporting truck. 1

The head of the screw 9i is housed in a cavity 32 of the ange. To adjust the screw 9| the table is moved by means of the pilot wheel 83 to bring the cavity 92 in register with an opening '93 in the guide plate 11 of the trackway, there being one of these openings in each of these trackway plates. A pivoted cover 94 for the opening is moved aside and atool is applied to the head of screw 9i to turn the same. Turning the screw down separates the front of the truck from the table iiange, moving the truck about the axle of wheel 18, which exerts an upward pressure on the ball 89 and the lflange 15 of the table 6l. y 'I'he ball and socket connection `enables the wheel to accommodate itself to the conditions of wear, etc.,y normally encountered in .apparatus of thisY character;` and by using :maderera in whicnallsoperations thereof may be.. speedily '2l-0 and accuratelyl accomplished, in which there is freedom. from vibration, and lin which Aa 'few simpleandl accessible: adjustments allow"r for regiulatingthe operations of, the l.machine to a' high,

degreefof refinement. l

'Modications kmay be madel inthe y.arrangement tand. location of a parts withinf the:- spi'rit and scope, of my invention, and: rsu'ch` modifications are intended .to be .covered 'by the vrappended claims.

-1. Av grinding machinecomprlsing' fa libase, a slidable table thereon, said table carrying'a grinding-element to .be aligned for performing the grinding operation, ,.trackways .over .whichl said table inoves,xmeansformoving theztable back andi forth, and means'. for:y supporting and adjusting the: table onv said trackways, such. means comprising-a tru-cl: adjacent each corner `of said table, a wheel in each truck on which thetable moves, a ball and ,socket-A connection between each truck andthe table .upon whichthe table is supported, andi an adjusting means engaging eachtruck to'adjust the positionfth'ereofito maintain said table level.

2. A grinding machinev comprising va base,.:a

slidable table thereon; said tablefcarryingr a grind'- ing4 element to be aligned "for performingA the grinding operation, trackways over which said table moves, means `for moving the vtable back and forth, and means for supportingand adjusting the' table on saidltrackways, such means comprising a'truck adjacent each 'corner of said table, a wheel in eachtruck onzwhich the table moves, a ball and socket connection between one end of each truck and the table, and an adjusting means having a pointed element engaging the oppositev end of each truck to adjust the position of the truck relative to said table and trackway.

3. A grinding machine comprising a base, a slidable table thereon, said table carrying a grinding element to be aligned for performing the grinding operation, trackways over which said table moves, means for moving the table back and forth, and means for supporting and adjusting the table on said trackways, such means comprising a truck, a wheel mounted therein fon which the table moves, a ball and socket connection between said truck and table, and means for adjusting the position of the truck so as to maintain said table level.

4. A grinding machine comprising a base, a slidable table thereon, said table carrying a grinding element to be aligned for performing the grinding operation, trackways over which said table moves, means for moving the table back and forth, and means for supporting and adjusting the table on said trackways, such means com'- prising a truck, a wheel mounted therein on which the table moves, a ball at one end of said truck upon which the table is supported, and an adjustable means' having a point upon whichthe table is supported upon the truck at the other end thereof.

5. A grinding machine 'comprising a base, a

slidable .table thereon,` said'ztable fcarryingy ra grinding: elementl ato bie aligned `for" performing thegzgrindin'g operation, trackwayszover which said 'tablezimoves .meansi'for moving :.thesftable back fand forth, y.andi 'means for supporting .and adjusting the tablefon said trackways, such means comprising .a truck,f.a wheel1mountedtherein on which the table moves, a ball at ionefendi of .said 'truckpluponf which .the table. is4 supported, zand: an adjusting. .means yengaging `the truck-'at sits'l op:-

posite-end to:adjust the position of 'thetruck'rto maintain saidftable'level.

f6.v SA grinding 'machine comprising a base, a slidable:tablefthereon,:said table. carrying 'ai grinding :element f-toV be :aligned for performing :fthe grinding operation,A `trackways -over Awhich `said table moves; meansv for moving the y'table back andforth, and..means for supporting.l and adjusting the'table'on saidptrackways, such means comprising a truck-adjacent;eachcorner ofsaid table, i

azwhe'el'fin Veach truckonwhichfthe table moves, and 'af pair of j ball: and socket connectionsibetween cache-truck andthe table,one ofwhich connectionsisadjustable.. i n v,

7.."A- grinding machine comprising ya 'basar-a slidablertable thereon-said-.table carryingfargrinding'relement tobe aligned for performing vthe grinding operation, trackways overv which' fsa'id tablewmoves, means for moving the tablelback an'dfortnand means for suppor-tingvand adjustingitl'iestable'. onssaid .atrackways suehf means comprising a truck.V adjacent each cornerof said table, `a wheel in each truck on which the table moves, a ball andl socket connection between-fone end iofreach truckand the table, an` adjusting screwffor each'truck,'the same being mounted'in vthetable and engaging the opposite end-of said tlfie:I motor is'moun'ted, laffhorizontalsupport for` the column, a horizontal` pivotal mounting for the column on the support, the pivot being below `the mounting of the motor, a lug on the column adjacent the support and spaced from the pivot, n

an adjusting screw movable in the lug and engaging the lsupport so as to tilt the column about its pivot, a lock nut for holding the screw in its vadjusted position, and a bolt passing through said adjusting screw and secured in said support for holding the column in adjusted position.

9. In a grinding machine, a motor, a' grinding head carried thereby, a column, a pivotalA mounting for the motor thereon, a support for the colf umn, a pivotal mounting for the column on its support, the pivots being disposed at right angles to each other and substantially perpendicular-to the motor shaft, means for adjusting the column about its pivot, and means for holding the motor and the column in their respective adjusted positions.

10. In a grinding machine, a motor, a grinding head carried thereby, a column, a pivotal mounting for the motor thereon, a slidable table on which the column is mounted, a pivotal mounting porting and adjusting the table on said trackways, such means comprising trucks adjacent the corners of said table, wheels in said trucks on which the table moves, a ball and socket connection between each truck and the table, and means for adjusting the position of the truck with respect to the table and about said ball and socket connection.

11. In a grinding machine, a motor, a grinding head carried thereby, a slidable support for the motor, a hollow column in which the support is slidable, means carried by the column and connected to the support for adjusting the position thereof in the column, and a counterbalance comprising a coiled spring pivotally connected to the support near one end, a lever pivotally mounted on the support near the opposite end, the free end of the spring being connected to one end of the lever, and a movable pivot connecting the opposite end of the lever to saidcolumn.

12. In a grinding machine, a motor, a. grinding head carried thereby, a slidable support for the motor, a hollow column in which the support is slidable, means carried by the column-and connected to the support for adjusting the position thereof in the column, and a counterbalance comprising a pair of coiled springs pivotally connected to the support near the top thereof and located on either side of the adjusting means, a shaft mounted on said support near the lower end thereof and close to a vertical line intersecting the upper connection of said springs, a pair of levers pivoted on said shaft, the free ends of said springs being connected to one of the ends of said levers respectively, and movable pivot connections between the opposite ends of said levers and said column.

13. In a grinding machine, a motor, a grinding head carried thereby, a slidable support for the motor, a hollow column in which the support is slidable,v means carried by the column and connected to the support for adjusting theposition thereof in the column, and a counterbalancecomprising a. coiled spring connected at one end to said support, and pivoted connections between said column and the otherl end of said spring so that thereof in the column, and a counterbalance com- Yprising a coiled spring pivotally connected to the support near one end, a lever pivotally mounted on the support near the opposite end, the freey end of the spring being connected to one end of the lever and a movable pivot connecting the opposite end of the lever to said column.

15. A machine tool comprising a base, a motor, a tool operated thereby, a horizontally slidable table on which said tool is mounted, trackways over which said table moves, means for moving the table back and forth, and means for supporting and adjusting the table ony said trackways, said means comprising a truck adjacent each corner of said table, a Wheel in each truck on which the table moves, and an adjusting means engaging the truck to adjust the position of said table.

16. A machine tool comprising a base, a tool,

a horizontal slidable table on which said tool is mounted, trackways over which said table moves, means for moving the table back and forth, and means for supporting and adjusting the table on said trackways, such means comprising wheels adjacent each corner of said table, at least one of said Wheels being mounted in a truck, a ball and socket connection between said truck and the table, and adjusting means engaging the truck to adjust the position of said table.

LAWRENCE B. PORTMAN.

RAYMOND H. PORTMAN.

FRANK J. ACTON. 

